Mechanical double action press using a link mechanism

ABSTRACT

A mechanical double action press using a link mechanism is utilizing four point link mechanism which is the simplest in construction, comprising main shafts extending from front to rear of a crown and having the length substantially equal to that in front to rear of it, one of said main shafts whereon inner slide driving gears being fitted, and another said main shaft whereon outer slide driving gears being fitted. In condition of operating, the speed in an idle stroke is higher than that in drawing work stroke, thereby it is possible to reduce the time required for one cycle.

United States Patent [1 91 Kawagoshi et a1. Nov. 20, 1973 [54]MECHANICAL DOUBLE ACTION PRESS 3,052,200 9/1962 Dehn et a1. 100/282 XUSNG A N C NIS 3,315,596 4/1967 Peters 100/282 3,695,090 10/1972 K118100/237 X Inventors: Tameo Kawagoshi; Kiyoji Aoshima, both of Komatsu,Japan Kabushiki Kaisha Komatsu Seisakusho, Tokyo-to, Japan Filed: Dec.29, 1971 Appl. No.: 213,431

Assignee:

Foreign Application Priority Data References Cited UNITED STATES PATENTSGeorgeff 100/282 X Primary ExaminerHarvey C. Hornsby AssistantExaminer-Arthur 0. Henderson Attorney-Town and McGeady [5 7] ABSTRACT Amechanical double action press using a link mechanism is utilizing fourpoint link mechanism which is the simplest in construction, comprisingmain shafts extending from front to rear of a crown and having thelength substantially equal to that in front to rear of it, one of saidmain shafts whereon inner slide driving gears being fitted, and anothersaid main shaft whereon outer slide driving gears being fitted. Incondition of operating, the speed in an idle stroke is higher than thatin drawing work stroke, thereby it is possible to reduce the timerequired for one cycle.

1 Claim, 6 Drawing Figures PAIENIEII IIUY 2 0 I975 SHEET 0F 5 INNERSLIDE STROKE OUTER SLIDE STROKE ONE CYCLE INVENTOR. 7 94 4'0 wean, I'YTI4009M,

INDIA 5Y5 MECHANICAL DOUBLE ACTION PRESS USING A LINK MECHANISMBACKGROUND OF THE INVENTION In mechanical double action presses usedheretofore, the inner slide is made to operate with a simple'crankmechanism, so that the maximum drawing speed in the drawing works islimited to a certain value according to the nature of the material.Generally, in press working, the drawing speed becomes equal to thepressing speed of the slide, so that the material may be broken when theslide speed exceeds the limit speed of the metal ma terial.

Accordingly, in the case'of a conventional press machine heretoforeused, when the number of strokes is increased simply to improve theproductivity, the critical drawing speed of the inner slide is exceeded,which results in the above-said drawbacks. Thus, it was'impossible toincrease production by increasing the num ber of strokes of the press.

In order to eliminate the above-described drawbacks, a number of movingmechanisms have been developed for reducing the time required for onecycle by increasing the idle strokes other than the period for drawingwork, that is, the approaching stroke up to"'the contact with themetal'material and return stroke after working, more than the speedatthe drawing work.

As for the mechanism for practising'andmotion; a press having four linkshas been suggested. With'this mechanism, however, although the linkmechanism it self is most simple, itis almost impossible, from itsconstructional pointof view, to apply it to a double action pressmachine. Thus, when it is intendedto carry out said motion inconventional double action presses, it was necessary to use an extremelycomplicated link mechanism, which was by no means adoptable for apractical use.

The applicant developed in the past a" mechanical double action pressusing a link mechanism as one utilizing above-said four-link on thedouble action press (Patent application'Ser. No. 28258/1966), but inthis case, the main shaft must inevitably be divided in] two because ofthe constructional restriction due to the front-to-back direction of thecrown proper from the particular construction of the double actionpress, which leads to poor accuracy and complicated construction,leaving numerous problems in practice.

With the above points in view, the present invention has succeeded inusing four linking mechanism which is the simplest in construction, andyet made it possible to pass the main shaft longitudinally throughthe'press, thus a mechanical double action press which can solve formerproblems concurrently.

SUMMARY OF THE INVENTION Still another object 'of the present inventionis to provide a mechanical double action pressusing a link mechanism, inwhich it is possible, ina presscycle,- to allot a longerst'roking timerequiredfordrawing 'work than time requiredfor lifting-"stroke of theinner'slide,

so that the drawing speed of the inner slide decreases considerably,whereby it beco'mesp'o'ssible to increase the number of strokes in unithour: of the press even when the drawing speed is'li'mited below'thecritical speed, accordingly the efficieney'of the pressing" work can beimproved remarkably.

Further object of the present invention isto'provide a mechanical doubleaction press-usin a link mechanism, in which an" eccentric wheel andaconnecting rod are used 'as the drivingsouree' of the outer slide, itbecomes possible to passthe main shaft through the crown body, sothatthe rigidity of the" main shaft is much' more increased, andmoreover',the bending of spective driving mechanisms of 'the' inner slide and theouter slide,-

FIG. 2-is a partly-broken'sectional view through a line A'- -A" in FIG;1* with the cover'removed,

FIG; 3is'a sectional view through a line B -Bin FIG. 1, I

FIG; 4is'a sectional 'view through a'line"C-C in FIG. 1

FIG; 5is a schematic representation of the link'ingrelation of thedevice shown in FIG. 1', and

FIG. 6'is a stroke diagram of the inner slide'a'ndthe outer slide in thedevice of the present invention.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to amechanical double action press using a link mechanism.

An example of the present invention" will now be described referring tothe'drawings'.

The press body 1 is constituted by combining an upper crown body 2, andupright 3, and a bed body 4 by tie rods 5,5, and in said crown body 2,each one of the right and left main shafts 6,6 pass through from thefront to the rear surface, both ends of thesemain shafts 6,6 are fixedon the crown body' 2by plates 7,7 as shown in FIG. 3 so that" the shafts6,6 will not b'e'transferred axially, and they are fixed by bolts 8,8,so that they are unable to'b'e rotated.

Driving gears 9, 9"are mounted on each of the main shafts 6, 6'. A drivegear 15 is rotated through a belt 11, a flywheel 12, a clutch 13, adrive shaft 14 and a pinion 14a by a motor 10 The drive gear 15 rotatesan intermediate gear 15a. As viewed in FIG. 1, the drive gear 15 issplined with ari'ght" pinion sha'ft'l'6' and the intermediate gearis-splined with a left pinion shaft 16a, so that as the drive gear 15'and intermediate gear 15a rotate, driving pinions 16b, 16b on theseshafts rotate and, in turn, rotate the driving gears 9, 9.

A driving link 17 is inserted into an eccentric circular plate portion9a which has an eccentric center with an interval (e) from the center ofthe driving gears 9,9 and is formed together, and the driving link 17 isconnected to one end of a rocker arm 18 through a pin 17a provided onthe upper end of the driving link 17. The other end of this rocker arm18 is connected to a rocker shaft 19, and is swingable with the rockershaft 19 as the fulcrum.

On the lower end of said driving link 17 there is pivoted the upper endof the link lever 21 through a pin 20, the lower end of this link lever21 is connected to a screw 23 through a pin 22. The screw 23 is fixedthrough thread on an inner slide 24, which is adapted to move the innerslide 24 up and down through the link lever 21 in response to thevertical motion of said driving lever 17. The relative position of theinner slide 24 relative to the crown body 2 is made adjustable by meansof the thread provided on this screw 23.

A pin 29 is provided displaced at a desired angle relative to saideccentric circular plate portion 9a provided at the driving gear 9mounted on said main shaft 6. With this pin 29, the end portion of aconnecting rod 28 and the tip end of the rocker arm 30 for the innerslide are connected to the eccentric wheel 27 fixed on the driving gear9 by means of a knock pin 25 and a bolt 26 and is eccentric with aninterval (e) from the center of the driving gear 9. The base end of therocker arm 30 is fitted onto said rocker shaft 19.

On the other hand, a rocker arm 32 at the side of the outer slide 31 ismade integral with said rocker arm 30 and the rocker shaft 19, so thatit is rotated for the same angle as this rocker arm 30.

The tip end of said rocker arm 32 is connected to the upper end of adriving link 33 inserted in said main shaft 6 through a connecting lever34 and pins 35, 36 at the both ends. The lower end of the driving link33 is connected to the upper end of a connecting link 38 through a pin37, the lower end of this link 38 is connected to a screw 40 through apin 39, and the screw 40 is threaded and fixed on the outer slide 31. Itis to be noted, as in the case of said inner slide 24, the relativeposition of the outer slide 31 to the crown body 2 is made adjustable bymeans of a thread provided on the screw 40.

In the drawing, the numerals 41, 42 designate balancers provided to makesmooth the raising and lowering of the inner slide 24 and the outerslide 31.

The operation of the device having the abovedescribed constitutionaccording to the present invention will be explained in the following.

The driving force of the motor causes to rotate the flywheel 12, aclutch 13, a drive shaft 14, and a pinion 14a, a drive gear 15, andintermediate gears a are rotated. Accordingly, as the drive gears 15 aresplined with the right pinion shaft 16, and intermediate gears 15a aresplined with the left pinion shaft 16a, respectively, so when the drivegear 15 and intermediate gears 15a rotate, pinions 16b, 16b rotate, too.Driving gears 9, 9 engaged with pinions 16b, 16b are rotated indirections shown by arrows.

With the rotation of the driving gear 9 on the side of fined as cycle Sshown by a chain line shown in FIG. 1. The inner slide 24 movingreciprocatingly up and down by the link 21 goes down slowly in thedrawing region, and after a slight pressing down at the lower deadpoint, moves to return quickly. On the other hand, with the rotation ofthe drive gear 9, the eccentric rings 27, 27 mounted on said drivinggear 9 swing the rocker arm 30. The rocker arm 30 swings the rocker arm32 for the same rotational angle through the rocker shaft 19, the rockerarm 32 rotates the upper end of the driving link 33 through the link 34,pins 36, 35. At the same time, the lower end of the link 33 givesvertical reciprocating motion to the outer slide 31 through the link 38,and when the outer slide 31 reaches to the lower dead point, the angleformed by the link 34 and the rocker arm 32 approaches about so thateven when the eccentric ring 27 rotates, the outer slide 31 remainsstandstill, and during this time inner slide 24 continues drawingoperation.

Considering the above-described motion in detail, the outer slide 31moves very slightly while it is positioned at the lower dead point, butsince this movement is confined within a swinging range which is quitesmall made by the link 34 with the pin 37 as the center which moves withan extremely small movement, the movement of the pin 37 itself becomesvery small. Accordingly, the movement of the pin 37 is so small that itis almost absorbed by elastic elongation of each part of link mechanismas seen from the movement of the outer slide 31, thus it will not reallygive movement for the slide 31.

FIG. 5 shows that the linking relation which drives the inner slide(indicated by a solid line) and the linking relation which drives theouter slide are (indicated by a dotted line) correlative.

Thus, as for the operating curve, it passes a slow descending curve indescending region a of the inner slide 24 as shown in FIG. 6, and at thetime of restoring to rise, it depicts a sudden sharp curve when itascends to an upper dead point. The outer slide 31 operates depictingsymmetrical curve both in the drawing region a and the returning period.

The desired standstill period at the lower dead point of the outer slide31 can be obtained by adjusting the length of a link 34.

What is claimed is:

1. A mechanical double action press using a link mechanism, comprising apress body, said press body including a bed body, an upright extendingupwardly from said bed body and a crown body spaced above said bed bodyand mounted on said upright, said crown body having a front side and anoppositely disposed rear side, an inner slide and an outer slide mountedin said press body for movement in the upward and downward directions, apair of main shafts disposed in spaced relation in said press body andeach said main shaft extending completely through said crown from itsfront side to its rear side as a single member, plates attached to theends of said main shafts and said plates rigidly fixed to said crownbody so that said shafts are not axially transferable and cannot rotate,one of said main shafts is associated with said inner slide and theother said main shaft is associated with said outer slide, a pluralityof driving gears rotatably mounted on each of said main shafts, aneccentric circular plate portion located on said driving gears mountedon said main shaft associated with said inner slide, an inner slidedriving link fitted to each of said eccentric circular plate portions, alink lever pin connected to said inner slide driving link and to saidinner slide, an eccentric wheel secured to each of said driving gears onsaid main shaft associated with said inner slide, inner slide, aconnecting rod mounted on each of said eccentric wheels, a rocker shaftspaced laterally from said main shaft associated with said inner slide,an inner slide rocker arm pin connected to said connecting rod at oneend and mounted on said rocker shaft at its other end, outer sliderocker arms associated with said rocker slide.

1. A mechanical double action press using a link mechanism, comprising apress body, said press body including a bed body, an upright extendingupwardly from said bed body and a crown body spaced above said bed bodyand mounted on said upright, said crown body having a front side and anoppositely disposed rear side, an inner slide and an outer slide mountedin said press body for movement in the upward and downward directions, apair of main shafts disposed in spaced relation in said press body andeach said main shaft extending completely through said crown from itsfront side to its rear side as a single member, plates attached to theends of said main shafts and said plates rigidly fixed to said crownbody so that said shafts are not axially transferable and cannot rotate,one of said main shafts is associated with said inner slide and theother said main shaft is associated with said outer slide, a pluralityof driving gears rotatably mounted on each of said main shafts, aneccentric circular plate portion located on said driving gears mountedon said main shaft associated with said inner slide, an inner slidedriving link fitted to each of said eccentric circular plate portions, alink lever pin connected to said inner slide driving link and to saidinner slide, an eccentric wheel secured to each of said driving gears onsaid main shaft associated with said inner slide, inner slide, aconnecting rod mounted on each of said eccentric wheels, a rocker shaftspaced laterally from said main shaft associated with said inner slide,an inner slide rocker arm pin connected to said connecting rod at oneend and mounted on said rocker shaft at its other end, outer sliderocker arms associated with said rocker shaft and displaceable throughthe same rotational angle as said inner slide rocker arm through saidrocker shaft, a vertically arranged outer slide driving link having anupper end and a lower end and mounted on said shaft associated with saidouter slide, an upper connecting link pin connected to said outer sliderocker arm and to the upper end of said upper slide driving link, and alower connecting link pin connected both to the lower end of saiddriving link and to said outer slide.